Herbicidal compositions and methods employing mono,di and tripyridine complexes of organo tin compounds

ABSTRACT

HERIBICIDAL COMPOSITIONS CONTAINING AS THE ACTIVE INGREDIENT THE MONO, DI AND TRIPYRIDINE COMPLEXES OF ORGANO TIN COMPOUNDS ARE DISCLOSED, AS WELL AS A METHOD FOR THEIR USE. EXEMPLIFYING THIS CLASS ARE COMPOSITIONS CONTAINING DIBROMOPROPYLTRIPHENYLTIN DIPYRIDINE COMPLEX.

nited States Patent Office 3,834,890 Patented Sept. 10, 1974 3,834,890 HERBICIDAL COMPOSITIONS AND METHODS EMPLOYING MONO, DI AND TRIPYRIDINE COMPLEXES OF ORGANO TIN COMPOUNDS Holger Meyer, Bromma, Sweden, assignor to Monsanto Company, St. Louis, M0.

N Drawing. Original application Nov. 21, 1966, Ser. No. 595,599, now Patent No. 3,661,911. Divided and this application Dec. 1, 1971, Ser. No. 203,864

. Int. Cl. A01n 9/22 US. CI. 71-94 2 Claims ABSTRACT OF THE DISCLOSURE Herbicidal compositions containing as the active ingredient the mono, di and tripyridine complexes of organo tin compounds are disclosed, as well as a method for their use. Exemplifying this class are compositions containing dibromopropyltriphenyltin dipyridine complex.

This is a division of application Ser. No. 595,599, filed Nov. 21, 1966, now -U.S. Pat. 3,661,911.

This invention relates to organotin compounds having the formula S N (CEHN) n 11 R wherein R is alkyl having from 1 to 5 carbon atoms; R and R each are alkyl having from 1 to 5 carbon atoms, phenyl, cyclohexyl, halogen, halo-substituted alkyl having from 1 to 5 carbon atoms or halo-substituted cyclohexyl; R is halo-substituted cyclohexyl or halo-substituted alkyl having from 2 to 5 carbon atoms; and n is an integer from 1 to 3.

The novel compounds display activity for combatting insects, fungi, weeds and microorganisms such as bacteria and viruses.

The compounds of this invention are readily prepared according to the following equation:

where R R R R and n are as above described. It is preferred that a suitable solvent be provided for the re action which can be a non-reactive solvent or an excess of pyridine. Ethanol is the preferred non-reactive solvent.

The reaction mass heated for a period of time and cooled. When the reaction medium or solvent selected is an excess of pyridine, a suitable solvent such as ethanol, ether, n-pentane, etc., is added to the cooled reaction mass and the reaction mass (with any added solvent) is further cooled to C. and kept there for a few hours. The crude product is filtered from the cold reaction mass and purified by recrystallization.

The invention will be more clearly understood from the following detailed description of specific examples thereof:

EXAMPLE 1 Diphenyltin dibromide 2.0 g. (4.62 mmoles) is suspended in 7 g. of pyridine. 3-bromocyclohexene (0.75 g., 4.62 mmoles) in 3 g. of pyridine is added and the mixture heated for 90 minutes at 50 C. on a water-bath. After cooling, ml. of ether is added, and the flask is kept at 20 overnight. The crude product is filtered off, washed with 25 ml. of ether and recrystallized twice from 20 and 15 ml. of ethanol. Yield: 2.2 g. (57.3%) of the tripyridine complex of dibromocyclohexyldiphenyltin bromide. Melting point 128-131". Salmon red crystals.

C l-I Br N Sn:831.07. Calc.: C, 47.69; H, 4.12; Br, 28.85. Found: C, 45.77; H, 4.28; Br, 28.62.

EXAMPLE 2 Diphenyltin dibromide (2.0 g., 4.62 mmoles) is sus pended in 7 g. of pyridine, and 3-bromocyclohexene (1.49 g., 9.24 mmoles) dissolved in 3 g. of pyridine was added. The reaction mixture is warmed on a water-bath at 50 for minutes. The color rapidly turns to dark violet. The mixture is cooled, and 20 ml. of ether is added. The reaction mass is stored at -20 for 2 hours. The crude product is filtered off, washed with 30 ml. of ether, and recrystallized from 45 ml. of ethanol after treatment of the solution with charcoal. Yield: 2.3 g. (75.8%) of the dipyridine complex of bis-(dibromocyclohexyl)-diphenyltin. Melting point 166. Pale red crystals.

C H Br N Sn=913.02. Calc.: C, 44.72; H, 4.20; Br, 35.01. Found: C, 45.15; H, 4.13; Br, 34.74.

EXAMPLE 3 Diphenyltin dibromide (2.0 g., 4.62 mmoles) is suspended in 15 ml. of ethanol, and allyl bromide (0.56 g., 4.62 mmoles) and pyridine (0.37 g., 4.62 mmoles) in 5 ml. of ethanol is added. On boiling, a colorless solution is obtained and the solution is maintained at reflux for 3 hours. The solution is cooled slowly and kept overnight at 20. A snow-white substance is filtered ofi and recrystallized from 12 ml. of ethanol. Yield: 1.3 g. (44.5%) of the pyridine complex of dibromopropyldiphenyltin bromide which melts to a viscous oil and decomposes at 152-159.

C H Br NSn=632.81. Calc.: Br, 37.89. Found: Br, 36.84.

EXAMPLE 4 Diphenyltin dibromide (2.0 g., 4.62 mmoles) is suspended in 10 g. of pyridine, and allyl bromide (0.56 g., 4.62 mmoles) is added. The mixture is heated for 90 minutes at 50 on a water-bath. The reaction mass is cooled and diluted with 25 ml. of ether. The reaction mass is then stored at -20 for several hours. The crude product is filtered off, washed with 50 ml. of ether and recrystallized three times from 2515 ml. of ethanol. Yield: 1.4 g. (42.6%) of the dipyridine complex of dibromopropyldiphenyltin bromide. Melting point 128- 131. Pale yellow crystals.

C25H25BI3N2SH=711.91. c3113.: C, H, BI, 33.68. Found: C, 42.52; H, 3.75; Br, 33.16.

EXAMPLE 5 Diphenyltin dibromide (2.0 g., 4.62 mmoles) is dissolved in 20 ml. of ethanol, and allyl bromide (1.12 g. 9.24 mmoles) and pyridine (0.73 g., 9.24 mmoles) in 5 ml. of ethanol is added. The mixture is boiled at reflux for 3 hours and then kept at 20 overnight. The crude product is filtered off, washed with 30' ml. of ether, and recrystallized from 18 ml. of ethanol. Yield: 2.6 g. (67.5%) of the dipyridine complex of bis-(dibromopropyl)-diphenyltin. Melting point 166-167".

C H Br N Sn=832.9. Calc.: C, 40.37; H, 3.63; Br, 38.38. Found: C, 41.67; H, 3.80; Br, 38.00.

EXAMPLE 6 2.0 g. of the dipyridine complex of dibrornopropyldiphenyltin bromide (2.80 mmoles) and 0.45 g. of 3- brornocyclohexene (2.80 mmoles) suspended in 9 g. of pyridine is heated on a Water-bath at 50 for 2 hours. The reaction mass is cooled and 45 ml. of ether is added. The reaction mass is kept at 20 for 2 hours. The crude product is filtered 01f, washed with 45 ml. of ether and recrystallized from 12 ml. of ethanol. Yield: 1.9 g. (78.1%) of the dipyridine complex of dibromopropyldibromocyclohexyl-diphenyltin. Melting point 147-149". Brownish crystals.

C H Br N Sn=872.96. Calc.: C, 42.65; H, 3.93; Br, 36.63. Found: C, 43.56; H, 4.03; Br, 35.95.

EXAMPLE 7 (a) Triphenyltin bromide (2.0 g., 4.65 mmoles) is dissolved in 10 g. of pyridine, allyl bromide (0.56 g., 4.65 mmoles) is added, and the solution shaken for a short period at 20. The solution, which immediately turned yellow, is heated for 2 hours at 50 on a waterbath. After cooling, 25 ml. of n-pentane is added and the reaction mass is cooled and maintained at -20 for a few hours. 2.8 g. of crude product is filtered ofl, washed with 25 ml. of n-pentane and recrystallized from 12 ml. of ethanol after treatment of the ethanol solution with charcoal. Yield: 1.65 g. (56.1%) of the pyridine complex of dibromopropyl-triphenyltin. Melting point 129- (b) A mixture of triphenyltin bromide (2.0 g., 4.65 mmoles) pyridine (0.37 g., 4.65 mmoles) and allylbromide (0.56 g., 4.65 mmoles) in 8 ml. of ethanol is boiled with reflux for 3 hours. The solution is cooled slowly and stored at 20 overnight. 2.45 g. of crude product were filtered OE and recrystallized from 12 ml. of ethanol after treatment of the ethanol solution with charcoal. Yield: 1.4 g. (47.8%) of the pyridine complex of dibromopropyltriphenyltin. Melting point 129130. White crystals.

C H Br NSn=630.0. Calc.: C, 49.57; H, 4.00; Br, 25.37. Found: C, 49.49; H, 4.27; Br, 25.27.

EXAMPLE 8 Triphenyltin bromide (2.0 g., 4.65 mmoles) is dissolved in g. of pyridine, and 3-bromocyclohexene (0.75 g., 4.65 mmoles) is added. The solution is heated on a water-bath at 50 for 90 minutes, and the color turned to wine-red after a few minutes. The reaction mixture is cooled, and 25 ml. of ether is added. After being kept at 20 for 2 hours the crude product is filtered off, washed with 25 ml. of ether and recrystallized from 20 ml. of ethanol after treatment of the ethanol solution with charcoal. Yield: 1.8 g. (57.7%) of the pyridine complex of dibromocyclohexyltriphenyltin. Melting point 131-132". White crystals.

4 C H Br NSn=670.06. Calc.: C, 51.98; H, 4.36; Br, 23.85. Found: C, 52.51; H, 4.49; Br, 23.41.

To illustrate the pesticidal and phytotoxic effectiveness of the compounds of this invention, the following examples are representative:

EXAMPLE 9 Six (6) parts per million of the dipyridine complex of bis-(dibromocyclohexyl)-diphenyltin completely inhibits the growth of Venturia inaequalis.

EXAMPLE 1O Dipyridine complex of dibromopropyl-triphenyltin A LD against midge larvae utilizing two (2) parts per million;

A LD 100 against young snakes utilizing one (1) part per million; and

A 0.2% solution by weight sprayed on two-week old wild oat plants provides a complete kill.

Although this invention is described with respect to specific examples, the details thereof are not to be construed as limitations except as indicated by the appended claims.

What is claimed is:

1. A composition comprising as an essential active ingredient therein a phytotoxic amount of the dipyridine complex of dibromopropyl triphenyltin and an inert solvent.

2. The method which comprises applying to wild oat plants a herbicidally effective amount of the dipyridine complex of dibromopropyl triphenyltin.

References Cited UNITED STATES PATENTS 3,361,554 1/1968 Weissenberger 71-97 3,222,158 12/1965 Sowa 7l97 2,580,473 l/1952 Sowa et al. 424245 2,867,566 1/1959 Weinberg 260-283 R 2,913,323 11/1959 Cameron 424-245 GLENNON HOLLRAH, Primary Examiner 

